.hover {
    animation: identifier 1.6s linear 0s infinite normal;
    position: relative;
    cursor: pointer;
}

.hover::after {
    position: absolute;
    display: block;
    content: '×';
    right: 0;
    top: 0;
    width: 16px;
    height: 16px;
    background-color: red;
    text-align: center;
    line-height: 16px;
    color: white;
}

@keyframes identifier {
    0% {
        position: relative;
        top: 0px;
        left: 0;
    }

    33% {
        position: relative;
        top: -15px;
        left: 0;
    }

    66% {
        position: relative;
        top: 15px;
        left: 0;
    }

    100% {
        position: relative;
        top: 0px;
        left: 0;
    }
}

body {
    background-image: url(background.jpg);
    background-size: cover;
}

#menu {
    width: 1200px;
    min-height: 30px;
    margin: 0 auto;
    padding: 20px;
    border: 3px solid rgb(168, 157, 166);
}

#menu>span {
    display: inline-block;
    padding: 15px 10px;
    background-color: #cc6ddf;
    margin-right: 10px;
}

h1>span {
    color: #d9534f;
}

h1 {
    text-align: center;
}

.btn {
    text-align: center;
}

.select {
    background-color: #1d69cb;
}

button {
    width: 80px;
    height: 40px;
    border: none;
    border-radius: 10px;
    margin-bottom: 20px;
    background-color: #087e16;
    color: white;
}

.del {
    background-color: #c23d11;
}

button:hover {
    cursor: pointer;
    background-color: #f68f0a;
}